Whole Body Scanning, Do You Really Need One?

Whole Body Scanning, Do You Really Need One?

Currently some medical imaging facilities are promoting a new use of computed
tomography (CT), also called computerized axial tomography (CAT) scanning. This
use is referred to as whole-body CT scanning or whole-body CT screening, and it
is marketed as a preventive or proactive healthcare measure to healthy
individuals who have no symptoms or suspicion of disease. At this time the
FDA knows of no data demonstrating that whole-body CT screening is effective in
detecting any particular disease early enough for the disease to be managed,
treated, or cured and advantageously spare a person at least some of the
detriment associated with serious illness or premature death. Any such
presumed benefit of whole-body CT screening is currently uncertain, and such
benefit may not be great enough to offset the potential harms such screening
could cause. Public health agencies and national medical societies-the American
College of Radiology, the American College of Cardiology, the American
Association of Physicists in Medicine, and the American Heart Association -do
not recommend CT screening.

CT is a diagnostic imaging procedure that uses x rays to obtain
cross-sectional images of the body. Since its introduction and rapid adoption
into medicine in the mid-1970s, CT has become recognized as a valuable medical
tool for the diagnosis of disease, trauma, or abnormality and for planning,
guiding, and monitoring therapy.

Important information regarding whole-body CT screening:

Such screening provides uncertain benefit with potential for some risk:
The most likely outcomes of CT screening of a healthy person with no
symptoms of illness are:

Normal findings or

Suspicious findings requiring follow-up tests

Normal findings carry the possibility of inaccuracy and false
reassurance. For suspicious findings, follow-up may involve simple,
non-invasive testing. It may also involve invasive procedures associated with
surgical risks of anesthesia, bleeding, infection, scarring, or it may entail
additional radiological exams, associated with radiation risk and the
potential risk of allergic reaction to injected contrast material. In any
case, it is unlikely that CT screening will benefit an individual lacking
signs or symptoms of disease by detecting a serious disease early enough to
treat it and alter the outcome significantly.

Radiation Dose: CT screening subjects the individual screened to
radiation exposure from x rays. The dose a patient receives during a typical
CT procedure is generally much larger than the radiation doses associated
with most conventional x-ray imaging procedures. The principal risk
associated with the radiation dose resulting to a person from a CT procedure
is the small possibility of developing a radiation-induced cancer some time
later in that person's life. For a patient with a medical need, the benefit
of a diagnostic or therapeutic CT procedure recommended by a physician
normally far exceeds the small cancer risk associated with a CT procedure.
For a person without symptoms, CT screening is unlikely to discover serious
disease, and the potential harm to the individual may be greater than the
presumed benefit.

Scientific Studies: There are no data demonstrating that
whole-body CT screening of individuals without symptoms provides a greater
probability of benefit than harm. Nor is there any scientific study known to
be underway to develop such data. Although there are several ongoing
investigational studies of the effectiveness of using CT to screen people,
the studies are focused on high-risk groups for specific diseases (e.g.,
cigarette smokers for lung cancer). In such studies only a limited portion
of the body is irradiated, not the whole body, and only screening for a
specific type of disease is being evaluated, rather than screening for just
anything that might be found anywhere in the body.

No Food and Drug Administration (FDA) Approval of CT for Screening: Statements by CT imaging facilities that imply FDA "approval,"
"clearance," or "certification" of CT for screening
procedures misrepresent the actual situation. FDA has never approved or
cleared or certified any CT system specifically for use in screening (i.e.,
of individuals without symptoms), because no manufacturer has ever
demonstrated to the FDA that their CT scanner is effective for screening for
any disease or condition.

No screening indication approved:
CT systems were manufactured and marketed for diagnostic use prior to the 1976 Medical Device Amendments and were placed in Class II based on the level of risk they present. These devices continue to be cleared for marketing for general imaging purposes. No data have been presented to the FDA to demonstrate that these devices are effective for screening, i.e., testing individuals without symptoms. Before FDA would allow such a claim or indication for use by the manufacturer, the manufacturer would have to provide valid scientific data for such a new use by submitting a premarket approval application for this new indication. This means that manufacturers of CT imaging systems cannot make claims that the products are intended to be used for screening non symptomatic individuals. Nevertheless, individual physicians may decide that a patient without symptoms can benefit from screening with CT even though data supporting such a use has not been submitted to the agency. Such use of a medical device is referred to as "off-label" use and is a judgment left to physicians. Sometimes insurance companies do not pay for such off-label use. However, statements that say or imply that FDA has approved CT scanning for whole-body screening uses are not correct.

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Medically reviewed by John A. Daller, MD; American Board of Surgery with subspecialty certification in surgical critical care July 14, 2017

This information has been provided with the kind permission of the FDA (www.fda.gov).